Among the metabolic reactions that are stimulated by phagocytosis is the respiratory burst. During the respiratory burst some highly reactive oxygen species such as O2, H2O2, and OH- are generated which in combination with lysosomal enzymes are able to kill a large number of microorganisms. Paraquat (methyl viologen) and nitrofurantoin were examined as to their chemical induction of "respiratory burst" by non-phagocytizing cells. These compounds would enter cells, accept electrons from one of the electron carriers and direct a portion of their electron flow to the production of O2, H2O2, and OH-. In addition, SOD, catalase and mannitol were examined as scavengers of these oxygen reactive species.